The Herald reports:
Genes play a large part in determining the sexual orientation of men, scientists have shown.
Genetic factors account for between 30 per cent and 40 per cent of what decides whether a man is gay or straight, according to the largest investigation conducted into the subject.
That sounds right. It’s not the only factor, but it is a very major factor.
The US researchers stress that environmental forces, such as hormones in the womb, play a more important role.
But they said this did not imply that upbringing or other social factors, or individual choice, had a bearing on sexual orientation.
“Sexual orientation has nothing to do with choice,” one of the lead researchers, Dr Michael Bailey, from Northwestern University in Chicago, said.
One study has suggested that if you have older brothers you are more likely to be gay, as the mother’s hormones try to “feminise” you.
The research involved testing the DNA in blood samples taken from more than 409 gay brothers and their heterosexual relatives.
It confirmed that a region previously linked to male sexuality on the X chromosome, known as Xq28, is more likely to be shared by gay pairs of brothers than siblings who do not have homosexuality in common.
A second genetic region, on chromosome 8, also appeared to increase the chances of a man being gay.
The future is fascinating we we get to understand DNA better.